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This article will briefly review some general
concepts related to the technical aspects of
performance measurement that managers
should be aware of in creating and using
performance measurement systems. These
concepts all relate to the following basic
principle of performance measurement:
Specific performance indicators represent a sample of all
the possible processes and behaviors that need to happen
so that the patients receive high overall quality care.
While the result of an indicator relating to
colon cancer screening has some intrinsic
interest, when managers offer substantial
monetary incentives and assess performance
through the use of such indicators the explicit
assumption is that they measure a broader
construct, such as a clinic's or hospital's overall
quality, or perhaps the state of primary
care or preventive care at a facility. Like the
more familiar sampling of people to estimate
a population characteristic, the indicators
must be sampled in such a way as to represent
the entire target population of indicated
processes and behaviors. Furthermore, the
sampling of indicators to estimate a construct
such as quality introduces another source of
uncertainty into the estimates. Standard performance
measurement approaches do not
adequately consider these issues.
First and most obviously, a performance
measurement system is irretrievably flawed
if the sampled measures do not adequately
represent the range of behaviors that are actually
important and that we should encourage.
A non-representative sample provides a distorted
measure of a broader construct such as
"primary care quality." A non-representative
sample also provides perverse incentives for
providers to abandon important processes of
care and concentrate on the incidental processes
that are over represented in the performance
measures.
Second, the usual aggregate scores such as
average pass rates—on all measured preventive
care or chronic care indicators for
example—do not adequately reflect the sampling
variability inherent in the choice of a few
indicators to represent a broader construct of
quality. The result is that these aggregate measures
may have a much higher noise to signal
ratio than is suspected and may not track well
any changes in practice by a provider or clinic.
This leads to cynicism and demoralizes those
profiled. One way to mitigate this problem is
to use a random effects or multilevel analysis,
which by explicitly modeling and removing
some of the measurement error, results in a
more precise quality score.
Third, in designing a performance measurement
system, it is important to find the
organizational level at which the variation
is located, and at which, a response should
occur. If a process varies across facilities
but not across providers within the facility,
and if the best approach to fixing the
problem is an organizational rather than an
individual one, then what is the point of
constructing provider level profiles?
A corollary of this last point is that if there
is not much variation, then there may not be
much point in measuring other than at the
population level. So, for example, if only 50
percent of patients get a recommended process
of care across a health care network and
there is little variation across providers relative
to this huge absolute gap (from 50 percent to
100 percent), then a network-wide remedy is
needed. Furthermore, to assess the remedy a
simple measurement based on a modest,
network-wide sample is all that is needed to see
how the rate changes. This task is much simpler
than implementing a performance measurement
system that must draw samples, calculate
rates, and educate individual providers.
Finally, managers should be relieved to know
that there is data to suggest that measurement,
feedback, and incentives using well
designed performance indicators, such as
some of the VA External Peer Review
Process (EPRP) indicators, do appear to have
a "halo" effect on indicators that are not part
of the active measurement and feedback set.1
However, this halo appears to extend only
across the same clinical condition and not
to unrelated clinical areas that are not part
of the current EPRP system. The implication
of this finding is not to start using poor
measures for clinical areas that we do not yet
monitor, but to recognize that performance
improvement using clinical indicators may
only be able to cover a finite amount of
the waterfront. While seeking the holy grail
of comprehensive automated performance
measurement, other established but often
under emphasized management tools—such
as an active and effective emphasis on the
perennial challenges of human resources and
staff morale—remain critically important to
maintaining and improving quality.
- Asch SM, et al. Comparison of Quality of Care for
Patients in the Veterans Health Administration and
Patients in a National Sample. Annals of Internal Medicine
2004; 141(12):938-45.
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